1. Field of the Invention
The present invention relates to a light-emitting device, and more specifically, to a light-emitting device capable of shading a contour of a light source and generating a vignetting effect by a structural design.
2. Description of the Prior Art
In popular display devices, such as an All-In-One PC, a liquid crystal display (LCD) monitor and a LCD TV, a functional indicator is often implemented by a light-emitting diode. Because the appearance of the conventional electronic device tends to be simple, the functional indicator is often implemented by shading a contour of a light source. A guiding column is used to sheathe the functional indicator on the light-emitting diode, and the light source is shaded by painting or plating around an opening of the light source, so as to shade the contour of the light source. However, it increases the manufacturing cost and spends much time in postprocessing, resulting in a poor yield rate. In addition, the light-emitting diode only needs a small driving current, and brightness of the light-emitting diode driven by the small driving current is very strong. A conventional method for adjusting the brightness of the light source is using a variable resistor, but an adjustable range of the brightness by the conventional method is limited, so that the light-emitting diode makes a user feel uncomfortable due to the strong brightness as the user sees the functional indicator. As a result, it is an important issue to design a light-emitting device which can not only shade the contour of the light source but also provide a comfortable brightness of the light source without additional manufacturing cost.